August 2007 at the Science & Industry Museum, Sandford Mill

Chelmsford Science & Industry Museum has a series of Open Sunday afternoons during August each year. CARS was invited to provide an Amateur Radio Station on the 5th, 12th, 19th & 26th this year.

5th August
The 5th of August turned out to be at that time the hottest day of the year with temperatures running about 30 degrees C. The previous day there were a number of Contests held with all bands "wide open" so the airwaves were electric. This, coupled with the high temperatures which forced people to visit the sea side meant that attendance levels were down and the 2 metre band absolutely dead!
Having said that, those that did attend were interested and enjoyed themselves.

CARS operated the 2 metre station manned by James, 2E1GUA using GB5HF with Colin, G0TRM, Malcolm, G4KGL, Geoff, G7KLV & John, G8DET in attendance.
How did it happen?...

On the previous Friday, Tony, G4YTG brought his specially designed and built Twin 5/8th over 5/8 Aerial. It is driven from the bottom via a Non-radiating stub - a technical first according to Tony.

Tony with the Twin 5/8th AerialAerial.
Photographs by John, G8DET

James (left) & Geoff tieing the rope to the pole & Tony pulling the ladder up to the roof.

The Twin 5/8th Aerial in position and showing the MFJ reading of less than 1.2 across the 2 metre Band.

James brought his '706 Transceiver and attached it to the coax cable provided on Friday.

James, 2E1GUA operating GB5HF inside the building on the landing floor

David Bolwell, Ex Marconi & Ex G3JCM operating GB5HF. This is the first Amateur contact David has made for 40 years. Behind is Colin reading and Malcolm.

Geoff, G7KLV & Trish operating GB5HF with Dr Geoff Bowles looking on (left). Trish was talking to Bev in Colchester who was testing out a new aerial and was operating from an Air Conditioned shack - wish we were!

Norwich was heard, Colchester & Kent were worked as was GB100J the Scouts in Hylands Park.

12th August
The weather forecast for the afternoon was rain, rain & more rain. In the event 10 spots fell & it was quite hot. Whether the poor forecast meant that people did not go to the coast we may not know - but they did come to Sandford Mill.

First in the door was Adrian, M0ABY & Mavis, G0XBC from Wheathampstead, they were there last week as well. The return trip is 48 miles so we were very pleased to see them again.

Similar to this time last year, the band conditions were diabolical, with a general noise on all HFs of 9+20 or worse. Most of it had a manmade component that compounded the problem but careful listening proved it was coming from the De-Humidifier at the end of the 2MT Hut - switched it off - gone.

Brian G3CVI brought along the Club's new rig, an IC756 but tuning it to the long aerial over the water proved to be different to using the FT847.

CARS used the usual the long-wire aerial over the water course which surrounds the Mill. This contributes enormously to the strong signal which radiates from G0MWT, however this does not completely overcome the Sun Spot Minimum (supposed to have ended December 2006!) which contributed to poor propagation conditions.

Trevor, M5AKA (left) talking to Clive King, M3HTD who has just passed the Intermediate Exam

The VHF Station with Bob, G4MDB & Jim 2E0RMI operating.

Looking at the VHF Station the other way with Murray, G6JYB in the frame.
Behind & to the left of Murray is Bernard Strutt, G1BJS from Kidderminster
who popped in on his way home from a cruise.

Bernard with his Brother & Geoff, G7KLV in the Tea issuing position.

Sandford Mill has just been presented by Mr Ellis of Margaretting (near Chelmsford) with a Marconi Marine AM Transmitter coded V5 and made between 1938 & 1946.

Don Manning (pictured below with his Wife) used to test these in 1946, 10 at a time on the bench.

Don Manning & Wife standing by the V5 Transmitter Rack.
The bottom panel is a Rotary Converter.

Brian looking on (left) with Malcolm operating the HF Station with
Adrian, M0ABY (extreme left) and his Wife Mavis, G0XBC right watching.

Don Manning & Wife with Geoff, G7KLV at the Tea Bar.

During the afternoon, Murray, G6JYB presented a beautiful Smith Chart Slide Rule to the Museum.

Trish Robinson, on behalf of the Museum, receiving the Smith Chart Slide Rule from Murray, G6JYB.
Photo by Trevor, M5AKA

The Smith Chart Slide Rule
Photo by Trevor, M5AKA

One problem encountered was that the HF Transmitter was interfering with the VHF Station due to the proximity of the VHF Aerial feeder. Also the Tree Cutting saw noise was drowning the Transmit audio! To solve this the VHF Station will operate on the 19th August from the 2MT, Marconi Hut.

19th August
The weather forecast for the afternoon was showers. It did rain at 2pm for 1/2 hour but then cleared up to a dry but steamy and cloudy afternoon - this was ideal as a number of people said the forecast was so poor they thought they would not venture too far - and came to Sandford Mill.

Jim, 2E1RMI turned up with his Wife Ann & set up the 2 metre station in the Marconi Hut using the extended aerial lead from G4YTG's Aerial on the roof. This transmitted well using GB5HF.

Bob, G4MDB appeared carrying his own FT747, PSU & Tuning Unit and connected it to the long aerial wire as a test to see if just 10 Watts on 160 Metres also interefered with 2 Metres. It did!

Tony, G4YTG next came through the door to hear about the interefence & soon produced a High Pass Filter for the 2 Metre Aerial Lead - this solved the problem by blocking the strong HF signal which was simply overloading the 2 Metre Receiver.

Members of the public were then appearing - guess what - Adrian, M0ABY and Mavis, G0XBC had come for the 3rd Sunday from Wheathampstead - nice to see them again.

Richard Meadows & his Father came into the Marconi Hut and appeared interested. It transpired that Richard was at school at King Edwards Grammar School & had attended the CARS Training Session & had passed the Foundation Licence exam. He had never actually transmitted on his own so Jim gave him a microphone and encouraged him to "have a go", which he did.

The VHF Station with Jim 2E0RMI & Richard operating. Dad is reading.

The HF & the VHF Station with Jim explaining his rig to Richard.
In the background Colin, G0TRM can be seen speaking to a visitor.

The HF with Malcolm & Bob. Bob produced a Handheld TX/RX
and tuned it in to Jim's frequency.

Richard with the Handheld using his own virgin Call-Sign M3SBU in QSO with Jim using GB5HF.

Richard reporting how he got on with the Handheld.
In the background Murray, G6JYB is talking to John, G8DET (red shirt)
Photo by Colin, G0TRM

The HF Station with Bob explaining the FT747 to Malcolm & Adrian & then Malcolm transmitting.
Looks like a No 19 set behind. Maybe a new aquisition.

A very good afternoon with lots of interest including a couple of people who would like to join the Foundation Course in January. A number of people had interest in the many exhibits as they had previously worked for or with the company, Marconi.

Next week, the 26th is the last Sunday Afternoon Opening at Sandford Mill.
Next event after that it is the Science & Discovery Day on Sunday, 23rd September, 10am to 5pm.
See you then?

Thanks to Dr Geoff Bowles for inviting CARS & to all CARS Members who made the events in August such a success.